Key clinical point: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors plus endocrine therapy (ET) led to a significantly higher improvement in overall survival than ET alone in older patients with hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2−) metastatic breast cancer (BC).
Major finding: ET+CDK4/6 inhibitor vs ET alone reduced mortality rate by 41% in the first-line treatment setting (adjusted hazard ratio [aHR] 0.590; 95% CI 0.423-0.823) and by 58% in the second-line setting (aHR 0.422; 95% CI 0.238-0.746).
Study details: This retrospective cohort study included 630 female patients aged ≥65 years with HR+/HER2− metastatic BC from the Survey Epidemiology and End Results (SEER)‐Medicare database , of which 461 and 169 patients received first‐line treatment with ET alone and ET+CDK4/6 inhibitor, respectively.
Disclosures: The acquisition of SEER‐Medicare data was supported by the University of Houston, Texas,College of Pharmacy. The authors declared no conflicts of interest.
Source: Goyal RK et al. Overall survival associated with CDK4/6 inhibitors in patients with HR+/HER2− metastatic breast cancer in the United States: A SEER-Medicare population-based study. Cancer. 2023;129(7):1051-1063 (Feb 9). Doi: 10.1002/cncr.34675